Means for operating car-brakes



(N0 ModeL) G. W. DARBY. MEANS FOR OPERATING GAR BRAKES.

No. 315,012. Patqnted Apr. 7, 1885.

UNITED. STATE s:

PATENT OFFICE.

GEORGE W. DARBY, OF ALLEGHENY CITY, PENNSYLVANIA.

' MEANS FOR QPERATING CAR-BRAKES.

I Anflvfiwa l SPECIFICATION forming part of Letters Patent No. 315,012,dated April 7, 1885.

Application filed October 15, 1884. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE W. DARBY, a citizen of the United States, anda resident of Allegheny City, in the county of Allegheny and State ofPennsylvania, have invented a new and useful means for operatingcarbrakes of that class wherein the brakes are caused to act byexhausting the air within a cylinder from one side of a piston andallowing it to enter at its normal or natural pressure on the oppositeside of the piston, whereby the brake in connection therewith may be setor released quickly and at will, of which the following is aspecification.

The invention I have made consists in the construction, combination, andarrangement of pipes and other parts with a valve-chamber containing asliding valve and such ports as will accomplish the object of myinvention, which will be readily understood from the followingdescription, taken in connection with the accompanying drawings,wherein- Figure 1 represents a side elevation of such parts as comprisemy invention as applied to a locomotive and its tender, as shown indotted lines Fig. 2, asection, on a horizontal plane, of the valve chestand the ports or openings therein; Fig. 3, a vertical central section ofsaid-valve-chcst and its valve therein Fig. 4, an enlarged verticalsection of that portion of the device wherein the exhaust is effected.

To put my invention into practical form I combine with the exterior ofthe locomotive at any convenient point or location thereon a rectangularvalve-chest, a, containinga suitable valve-seat, I), through which arethree ports or openings, 0 d 6, covered by a hollow sliding valve, f,provided with an operating rod or stem, 9, all of which are very similarto those in use on, many small steam-engines. From each of the twooutside ports, 0 e, an independent pipe, h and i, extends to and is madeto communicate with the interior of a closed cylinder, j, arrangedunderneath the tender or car for operating its brakes. One of thesepipes is joined to one end of said cylinder 9 and the other pipe to itsopposite end.

The central port, d, is provided with a vertical exhaust-pipe, k, thatextends upward through the roof of the cab, and the middle section ofthis pipe k is somewhat enlarged or swelled to increase the size of itsinterior at that point. In the side of this swelled portion Z of theexhaustpipe 7c is entered and curved upwardly a smaller pipe, m,.theinner end of which terminates just above the aforesaid enlargement Z,the other end being in communication with a vertical close chamber, an,adjacent thereto, which chamber 12 is provided with an outwardly-cxtending trumpet'shaped month, 19, wherein is located the nozzle orcontracted end of a small pipe, 1", connected with the boiler of thelocomotive, and provided with a suitable cook, 23, for the admission andregulation ofsuch steam as may be required.

The several parts having been constructed,

combined, and arranged with respect to each.

other in the manner shown and described, upon the admission of livesteam under pressure from the boiler to the pipe 1', leading into thetrumpet-shaped mouth 1) of the vertical chamber 11,, it will quicklypass therefrom directly into and through the short curved pipe m,extending upward in the exhaustway It,

driving before it all the air found therein, and producing a strongsuction on the central port, d. Now, if the valvef, by means of itslever s, be so moved or shifted on its seat as to bring the centralport, d, in communi cation with either of the other two ports, the

air will be speedily drawn from that end of the cylinder in connectiontherewith, producing a partial or complete vacuum proportioned to theforce of the steam. At the same time the air will enter the opposite endof the cylinder through that pipe in connection with the uncovered portin such a manner as to act directly against the piston within thecylinder and force it in one direction, and which may be reversed by asimple changein the position of the valve.

Having thus briefly described my invention and its mode of operation, Iclaim- 1 As a means for operating car-brakes by atmospheric-air pressureon one side of a piston in connection with a complete orparpipe-supplied with an inlet for live steam, tial vacuum on the otherside, the combinaand a stop'cock or means for controlling the tion of avalve-chest containing openings or same.(

ports for the admission or Withdrawal of air GEORGE W. DARBY. 5 from acylinder and pipes communicating Witnesses:-

therewith, a valve that shall slide over, close, M. E. HARRISON,

open, and operate said air-ports, an exhaust- E. I. HARRISON.

